| 摘要 |
<p>981,894. Valves. BABCOCK & WILCOX CO. Jan. 23, 1962 [Jan. 23, 1961], No. 2420/62. Heading F2V. A check valve comprises a housing 12 having an inlet 14, an outlet 16 and a valve closure member 28, which may be weight-loaded, pivoted at 30. The housing is shaped at 34 to provide a ratio of flow area between the periphery of the closure and the housing and flow area between the periphery of the closure and the seat within the range of 0À8 to 1 substantially throughout the whole valve movement. The shape 34 provides a ratio of 1 over the majority of the valve movement while a shape 36 provides a ratio varying between 0À8 and 1, it being 1 nearer the closed position. The line 38 indicates a known shape in which the ratio varies between 0À3 and 1. A cover 20 faciliates assembly and repair of the valve. U.S.A. Specification 2,864,401 is referred to.</p> |
